Ruby dates Rhun, and so does Dark...

So it's like this: Rhun and Dark separate from time to time, and Dark is allowed to show himself whenever he wants. They both love you, in their own way...

You're also a Guardian, like Rhun is a Tooth Fairy. Guess what? You also have a Dark Side, only it's called Dahlia. She looks like Dark, but female. Your White version also looks almost like Rhun's. When you're united with Dahlia, your outfit is also like Rhun's.

Dahlia and Dark are together, just like Rhun and you

Right now you (together with Dahlia) are reading a book, Meanwhile, Rhun is playing chess with Dark